This invention relates to a method and apparatus for unplugging fire hydrant drain holes, sometimes referred to as weepholes.
Standard fire hydrants consist generally of a standpipe or barrel which is set in concrete or the like at ground level and which connects underground to a water supply. The barrel has a side-opening pumper nozzle outlet above ground level which is enclosed by a cap when not in use and a valve below ground level for controlling the water supply to the nozzle. The valve includes a valve plate or the like which seats at the lower end of the barrel and which has a stem extending to the upper end of the barrel where it is attached to an exposed operating nut which is rotated to open and close the valve thereby controlling water supply to the pumper nozzle.
In use of a hydrant, when the valve is opened, water fills the barrel and discharges through the pumper nozzle (with the cap removed). Then, when the valve is closed, after operation, an amount of water collects in the barrel above the valve. In order to drain the collected water from the barrel, for example so as to prevent freezing of the water and possible bursting of the equipment, fire hydrants commonly are provided with one or more drain or weepholes just above the valve seat and through which the collected water can drain away into the earth.
It is necessary, for adequate drainage of the collected water, that the drain holes are kept open, and this is usually effected by back-flushing the hydrant, namely opening the main valve with the pumper nozzle cap kept in place. Despite such treatments, however, the drain holes may still tend to clog with rust or dirt in general, in which case the hydrant barrel does not drain effectively, and it becomes necessary to unplug the drain holes. Commonly, this is done by digging around the hydrant through the concrete or the like in which it is embedded, to a depth of about 6 feet, to provide access to the drain holes, from the exterior of the hydrant. The digging and drain hole clearance can be an extremely time consuming operation, which can take 4 men upwardly of from 14 to 32 hours.
It is accordingly an object of the invention to provide a method and apparatus for unplugging fire hydrant drain holes, which does not involve digging around the hydrant, and which is accordingly speedier and more effective than known techniques. A more specific object of the invention is to provide a fire hydrant drain hole unplugging method and apparatus, the latter being in the form of a drilling-type tool which is used from inside the hydrant by prior removal from the top of the hydrant of the relevant bonnet and valve gear.
Applicant is aware of the following U.S. patents pertaining to drilling devices and the like. None of the patents, however, discloses or suggests a method and apparatus for unplugging fire hydrant drain holes as in the present invention.
U.S. Pat. No. 836,212, Nov. 20, 1906;
U.S. Pat. No. 1,866,714, July 12, 1932;
U.S. Pat. No. 2,333,025, Oct. 26, 1943;
U.S. Pat. No. 2,487,203, Nov. 8, 1949;
U.S. Pat. No. 2,958,349, Nov. 1, 1960;
U.S. Pat. No. 3,016,073, Jan. 9, 1962;
U.S. Pat. No. 3,697,188, Oct. 10, 1972;
U.S. Pat. No. 4,184,795, Jan. 22, 1980.